Panoramic optical systems which can be employed to provide a 360° field of view, are known. By way of example, U.S. Pat. No. 6,459,451 discloses a catadioptric lens which provides a 360° field of view. Such optical systems can be used advantageously with a camera to provide a system capable of imaging an entire 360° field such as an entire room or landscape from a unitary location using a single camera without requiring scanning or stitching multiple images. However, such lenses provide an image which is not readily interpretable by observers unless the image is first “unwrapped”. The image of a 360° field of view lens is annular or doughnut-shaped and is therefore distorted and not readily discernible by a human observer. It is therefore necessary to convert that image or “unwrap” it into a relatively two-dimensional format such as a horizontal view on a relatively flat medium such as physically on film or electronically on a computer screen. The unwrapping process consists of a mathematical transformation such as by conversion of each picture element or pixel and is preferably accomplished in a manner which results in little or no distortion which would otherwise reduce the quality of the resulting flat image. Such pixel-by-pixel transformations are typically very complex and require complicated and time consuming computer programs, especially for reasonable levels of resolution and images having large numbers of pixels. Consequently, it has not been possible heretofore to exploit panoramic lens technology to provide a real-time unwrapped video image with acceptable resolution.
A system which could provide real-time unwrapped video images derived from a panoramic lens and video camera would be highly advantageous for a variety of useful applications. By way of example, such a system could provide security surveillance over a continuous all-around field of view using a unitary display with just one observer. Such a system could also be mounted on a transport mechanism and used for military or police reconnaissance purposes or for robotic imaging. It could also be used for medical visualization and for traffic awareness systems. It can be tailored to be compatible with internet transmission, wireless systems and can be designed for video image compression to reduce transmission bandwidth requirements. Once it becomes convenient to “unwrap” a panoramic video image in real time with little or no distortion and with an acceptable level of resolution, a host of useful and advantageous applications become feasible and readily available.